I get the impression that some people see the words 'diffraction' and 'limit(ed)' in close proximity and freak out without reading what I've written.

I think you've put your finger on it. It seems that a number of your interlocutors have become so invested in (correctly) debunking claims that peak resolution depends on sensor resolution or that lower sensor resolution can combat the effects of diffraction that they can't admit that sensor resolution can have any impact on our ability to perceive the effects of diffraction in actual photographs. If I understand you, you're saying merely that higher resolution sensors will enable us to see more subtle diffraction effects than lower resolution sensors will; a suggestion which I wouldn't have thought to be controversial.

...that the system that is "diffraction limited" at the wider aperture is the higher resolving system. For example, if System A is "diffraction limited" at f/4 and System B is "diffraction limited" at f/8, then System A is the higher resolving system, all else equal.